Aśauca-vidhi (Rules of Impurity) within Śrāddha-kalpa — Chapter on Testing/Selecting Brahmanas and Honoring the Atithi
यश्चरेद्विधिवद्विप्र समा द्वादश संततः / त्रिनाचिकेतस्त्रै विद्यो यश्च धर्मान्द्विजः पठेत्
yaścaredvidhivadvipra samā dvādaśa saṃtataḥ / trināciketastrai vidyo yaśca dharmāndvijaḥ paṭhet
O vipra, one who practices continuously for twelve years according to the ordinance is called trināciketa and traividya; and so too is the twice-born who recites the dharmas.